The present invention relates to a method for manufacturing a disc-shaped curved magnet coil, especially for a system for accelerating and/or storing electrically charged particles such as electrons, wherein the conductors of the coil to be manufactured are arranged about a winding core having a convex outside and a concave inside and therefore, with a partially negative curvature, and are thereupon fixed in their appropriate position. The invention further relates to apparatus for implementing this method.
Such a magnet coil is known, for instance, from the publication "Fuji Electric Review", vol. 19, No. 3, 1973, pages 112 to 118. This coil, wound of superconductors, is curved along an arc length with predetermined radius and predetermined arc (sector) angle, so that it has a convex outside and a concave inside. The magnet coil, the conductors of which are secured by struts between these sides in their geometric position, is to serve as a lifting magnet for the contactless suspension guidance of a vehicle along a track.
Also in particle accelerators, storage rings for charged particles such as electrons must have appropriately curved dipole magnets due to their curved particle tracks. These magnets can be bent, in particular, in the shape of semicircles (see, for instance, "IEEE Trans. on Nucl. Sci.", vol. NS-30, No. 4, August 1983, pages 2531 to 2533.) Because of the required high field intensity, superconducting windings are provided preferably for this purpose (see, for instance, also "Technical Report of ISSP"-the Institue for Solid State Physics-the University of Tokyo, Japan - Ser. B, No. 21, September 1984, pages 1 to 29).
In order to guarantee an unchanged position of the turns of these windings to be fabricated from appropriate conductors, they must first be wound about an appropriately formed winding core and fastened to the latter. The problem arises, however, of winding a coil with a negative radius of curvature in the region of the concave insides of such winding cores.
Magnets, the windings of which have negative curvature, can be manufactured, for instance, by laying at least one conductor in slots without tension and subsequent wedging. Also known in successive clamping of the conductor, using special contacting elements such as individual clamps on the outside rim of an appropriately shaped winding core in fixed relationship. The conductor sections clamped-on by these elements must then be fixed section by section on the winding core or, if necessary, on conductor turns already applied to them, for instance, by cementing. Such winding techniques, however, are very elaborate and time-consuming, especially for the manufacture of superconducting dipole magnets of storage rings.